ctools

I discovered an interesting bug in csiactcopy:
In case the user provides a runlist that should be copied (instead of the full dataset), the tool issues a command to open the index files only for the given runs. The command looks the following:

selection = "" 
selection += "["+hduname+"][" 
for run in self._runs:
    selection += "OBS_ID=="+str(run)
    selection += "||" 
selection = selection[:-2]
selection += "]" 
openstring = filename + selection
fits     = gammalib.GFits(openstring)

As soon the runlist exceeds 68 entries (both on MacOSX and Scientific Linux), the last command throws an exception with FITS error status 125. Apparently, the openstring passed to GFits becomes simply too long to be processed by cfitsio.

I suppose there are three options to tackle this:

1. Throw an error in csiactcopy if the runlist exceeds e.g. 60 runs (instruct the user to split list into chunks and run csiactcopy several times)
2. Fix the issue in csiactcopy that internally the runlist gets chunked into pieces of maximum 60 runs (might imply some work and testing)
3. Enhance GFits to allow for such long selection strings (e.g. by chunking internally and merging)

I have checked the following page:
https://heasarc.gsfc.nasa.gov/ftools/fv/doc/expressions.html
There it says: “The expression can be an arbitrarily complex series of operations performed on constants, keyword values, and column data taken from the specified FITS TABLE extension. For the case of row filtering, the expression must evaluate to a single boolean value for each row of the table.”